On 05/16/2017 07:27 PM, Ming Lei wrote: > When one NVMe PCI device is being resetted and found reset failue, > nvme_remove_dead_ctrl() is called to handle the failure: blk-mq hw queues > are put into stopped first, then schedule .remove_work to release the driver. > > Unfortunately if the driver is being released via sysfs store > just before the .remove_work is run, del_gendisk() from > nvme_remove() may hang forever because hw queues are stopped and > the submitted writeback IOs from fsync_bdev() can't be completed at all. > > This patch fixes the following issue[1][2] by moving nvme_kill_queues() > into nvme_remove_dead_ctrl() to avoid the issue because nvme_remove() > flushs .reset_work, and this way is reasonable and safe because > nvme_dev_disable() has started to suspend queues and canceled requests > already. > > [1] test script > fio -filename=$NVME_DISK -iodepth=1 -thread -rw=randwrite > -ioengine=psync \ > > -bssplit=5k/10:9k/10:13k/10:17k/10:21k/10:25k/10:29k/10:33k/10:37k/10:41k/10 \ > -bs_unaligned -runtime=1200 -size=-group_reporting -name=mytest > -numjobs=60 > > sleep 35 > echo 1 > $SYSFS_NVME_PCI_PATH/rescan > echo 1 > $SYSFS_NVME_PCI_PATH/reset > echo 1 > $SYSFS_NVME_PCI_PATH/remove > echo 1 > /sys/bus/pci/rescan
The patch looks good to me. But since you have a nice reproducer, how about turning that into a blktests [1] test case? [1] https://github.com/osandov/blktests -- Jens Axboe
